Apparatus for treating finely divided materials with gaseous fluid

ABSTRACT

A method for treating finely divided materials with a treatment fluid (steam), particularly for conditioning oil containing vegetable raw materials in which one or more vibratory conveyors with a perforated bottom has treatment fluid introduced through at least one inlet opening under the perforated bottom. The larger particles formed by clotting during the action of the treatment fluid are pulverized by pulverizing members and an additional perforated plate. The conditioned materials are dried in hot air.

CROSS-RELATED APPLICATION

This application is a division of co-pending application Ser. No.501,824 filed Aug. 29, 1974 and now U.S. Pat. No. 3,972,278 and claimsthe priority of the application filed in the Netherlands on Aug. 31,1973.

BACKGROUND OF THE INVENTION

My invention relates to a method of treating finely divided materials inwhich an apparatus is employed with a treatment fluid, particularly forconditioning oil containing vegetable raw materials, comprising one ormore vibratory conveyors with a perforated bottom and at least one inletopening under the perforated bottom, for introducing a treatment fluid.

Such a device for treating finely divided materials with gaseous media,e.g. for drying sugar, is known per se. In order to prevent in thisknown device the perforated bottom from becoming obstructed, when dryingmaterials, said bottom is covered for example with flexible sheets,whereby incrustation of the transport surface is avoided.

Though this device is suitable for preventing incrustation it can not beused to pulverize sufficiently the lumps produced by clotting. This is aconsiderable disadvantage when pre-treating oil containing vegetable rawmaterials, while moreover the difficulty is met that during the steamtreatment in the first stage of the treatment of oil containingvegetable raw materials, clotting of the pulverized oil containingvegetable raw materials occurs. These clots of material cannot be driedin the normal drying time and constitute, after normal drying, anuntreatable product.

Clotting and adherence of the raw material to the bottom of a vibratorconveyor is substantially produced in the first stage of heating andhumidifying the pulverized oil containing vegetable raw materials. Clotspulverized after this stage do not show these symptoms when they arefurther heated and exposed to the effect of steam for humidification.When the treatment is performed under the right circumstances, thealready partially pre-treated oil containing raw material has moreoverafter humidification, still sufficient agglomerating properties to bindthe dust meanwhile formed during pulverization, so that a product withexcellent extraction properties is obtained.

Since the structure of the raw material after it has passed through thefirst stage of thermal treatment, that is to say: heating andhumidification by means of steam, has been changed such that already onminor pressure oil issues, whereby balls form which cannot be treatedany further, pulverization should be performed with great care.

SUMMARY OF THE INVENTION

My invention aims to provide a method which does not present theaforementioned disadvantages and in which lumps formed in the firststage owing to clotting, can be pulverized, while after pulverizationthe material can bind again the dust formed during this process and aproduct is obtained with excellent extraction properties.

This is attained by the arrangement in which the device is provided withpulverizing members for pulverizing the greater particles, formed byclotting, during the action of the treatment fluid.

The pulverizing members comprise advantageously a plurality of spacedrods disposed behind one another which are arranged at least over afirst bottom part of the perforated bottom.

By using such rods it is possible to achieve a sparing pulverization ofthe material.

It is very advisable that the rods consist of a first stationary unit ofa row of rods, which either cooperate with the perforated bottom or areat a minor height over this bottom and a second unit of a row of rodsslightly spaced above the first stationary unit, while the second unitis secured such that it can move along with the vibratory conveyor.

When using a first stationary unit the difficulty may arise that thetransport of material by the conveyor is hindered and sometimes does nottake place at all. These difficulties are alleviated by means of asecond unit of a row of rods disposed at some distance e.g. 1.5 to 2 cmover the first unit. A very favorable effect of this construction isthat clots formed in the first stage of the humidification and heatingof the oil containing vegetable materials, are broken when passing bythe two grid moving relative to one the other.

In order to keep the perforated bottom of the vibratory conveyor clean,the distance between the rods of the first unit should be at least equalto the stroke length of the vibratory conveyor.

The rods of the first unit are efficiently united to a frame work,whereby they are positioned over the bottom with a minor clearnace. Thussubstantial wear of the perforated bottom is avoided.

With particular advantage, the pulverizing members further comprise asieve bottom, extending over a bottom part of a second vibratoryconveyor, which follows on a first bottom part, the second vibratoryconveyor being at a lower level than the bottom part of the firstvibratory conveyor, while the sieve bottom is aligned with the bottompart of the first vibratory conveyor and the first stationary unit of arow of rods and the second unit of a row of rods, which is movable alongwith the vibratory conveyor, extend over this sieve bottom.

The material passing through the sieve bottom can thus take a particularsize, while moreover optimal results may be achieved, when the partiallypre-treated material immediately after pulverization has been broughtinto contact with the steam required for the continuation of the thermaltreatment, since every particle after it has passed through the sievebottom and had fallen to the bottom of the second vibratory conveyor,which is at a lower level, can be separately "washed" by the steam. Inthis way a product is obtained, in case of oil containing vegetable rawmaterials, which lends itself particularly well for extraction purposes.

The invention contemplates a method for conditioning oil containingvegetable raw materials, the oil containing product being conveyed andthe pulverized raw materials subjected to a treatment by steam andsubsequently to a treatment with a drying gas, characterized in thatclots formed during the first humidification are subjected to apulverizing treatment and preferably the material obtained during thispulverizing treatment is further brought into contact with steam suchthat each particle is individually washed by the steam.

The latter condition is satisfied by the arrangement that the particlesafter pulverization, are caused to fall through a steam containingmedium.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows schematically a device for carrying out the methodaccording to the invention;

FIG. 2 shows partially a longitudinal section through such a device;

FIG. 3 is a cross section taken on line III--III in FIG. 2, and

FIG. 4 is a plan view.

DESCRIPTION OF PREFERRED EMBODIMENTS

In FIG. 1 there is represented in outline a device for treating finelydivided materials with gaseous meda. Hereinafter the treatment isfurther clarified with reference to the process of conditioningpulverized oil containing vegetable products but it is obvious that thedevice can also be used for many other finely divided materials whichcan give rise to the formation of clots during treatment with gaseousfluids.

The device for treating finely divided materials with gaseous mediacomprises a vibratory conveyor casing 1 with a perforated bottom whichis subdivided into a first bottom part 2' and a second bottom part 2".The second bottom part 2" is situated at a level lower than of the firstbottom part 2' of the perforated bottom of the vibratory conveyor 1. Thevibratory conveyor is provided with an exhaust hood 3 with an inlet 4for feeding the finely divided materials. On the exhaust hood 3 on theinner side thereof is a partition 5 extending to a position several cmabove the stream of raw materials moving through the apparatus. There isfurther provided an outlet 6 for discharging the treated materials. Thevibratory conveyor is divided into two parts by means of the partition5, to wit, a first part or conditioning part 7 and a second part ordrying part 8, wherein the oil containing material is dried to thepercentage of moisture required for the extraction.

For feeding a gaseous fluid to a chamber 26 which is underneath theperforated first bottom part 2' of the vibratory conveyor, there ispresent at least one gaseous medium inlet 9 for feeding steam. Generallysuperheated steam coming from a heat exchanger 10 and to which 5 to 10%of air is admixed, whereupon the mixture is supplied to the chamber 26,is used in treating and conditioning finely divided oil containingvegetable raw materials. In connection with the thermal economy, theair, after it has passed through the raw material to be treated, passesvia a medium outlet 24, to a heat exchanger 11 and is heated again tothe steam temperature and thereupon, mixed with steam by means of blower12, introduced into the chamber 26.

The device is further provided with another inlet 13 for the gasousmedium (in this case there are three such inlets), whereby air heatedvia a heat exchanger 14 can be passed by means of a blower 15 to theinlets 13 for the gaseous medium, so that the material treated can bedried . An exhaust device in the form of a blower 16 is arranged fordischarging the exhaust drying air.

For oscillating the vibratory conveyor with the perforated bottom, thedevice is provided with springs 29 which are secured to frame 30 and tocasing 1 of the vibratory conveyor.

The perforated bottom of the vibratory conveyor 1 is, as mentionedhereinbefore, divided into two parts 2' and 2", the parts being situatedat different levels. In addition thereto, the perforated bottom part 2'is continued by a sieve bottom 17 extending over the part of aperforated bottom part 2", to wit in the entire length of the chamber28.

It is obvious that instead of using one vibratory conveyor with bottomparts 2' and 2" more vibratory conveyors arranged in cascade could beused, that is to say a separate vibratory conveyor with the bottom part2', a second separate vibratory conveyor with a sieve bottom over thebottom part 2" proper as far as chamber 28 extends, a third vibratoryconveyor with chamber 28, a fourth separate vibratory conveyor withchamber 27 and so on.

The partition 5, extending in operation several cm over the stream ofraw material moving through the apparatus, allows exhaust of thevapor-air mixture from the first or conditioning part 7 separate fromthe exhaust drying air from the second or drying part 8 via the outlets24, 25, respectively.

When more individual vibratory conveyors are used, such a partition, canbe omitted.

When oil containing raw materials are treated, sieve bottom 17 extendsthe entire length of the bottom part 2" of the vibratory conveyor whichextends over chamber 28.

The materials falling through sieve bottom 17 are washed by steam whichis supplied via chamber 28 and perforated bottom 2". This treatmentresults in a product which lends itself extraordinarily well toextraction. Moreover, dust formed during pulverization is bound by theproduct obtained during this second action of steam.

Thereupon the oil containing material can still be subjected to atreatment by steam supplied via chamber 27.

The device is also provided with a first unit 18, comprising a pluralityof rods 19 in a frame, the rods 19 being disposed with minor clearancerelative to the first bottom part 2' of the perforated bottom, in orderto avoid wear of the part 2' of the vibratory conveyor. This unit 18 issecured by means of a rod 20 to a support 21, so that when the vibratoryconveyor is moving, the rod 20 with the unit 18 and associated rods 19remains stationary. The stroke length of the vibratory conveyor issubstantially equal to the distance between two consecutive rods 19,whereby the entire perforated part 2' of the bottom of the vibratoryconveyor can be kept free from incrustations.

Since there is a risk that the transport of material with such astationary unit 18 having rods 19 is hindered or even becomes completelyimpossible the device is also provided with a second unit 22 of rods 23,which can move along with the vibratory conveyor, while the spacing ofthe rods 23 with respect to each other may correspond to the strokelength of the vibratory conveyor. Due to the cooperation of the rods 22and the rods 19 agglomerations of pulverized material are pulverizedagain. Owing to suitable selection of the size of the openings of thesieve bottom (e.g. 6 mm) material with a particular size can fall,through a steam medium coming from chamber 28, on the second bottom part2".

The first space 7 which is underneath hood 3 can be separated by meansof partition 5 from the second space 8 which is located to the right ofthe hood and the partition 5. The space 7 is provided with outlet 24leading to the heat exchanger 11.

In addition thereto the second space 8 is provided with secondsection-outlet 25 which is connected to the exhaust device representedby the blower 16.

The rods 19 and 23 are shaped as bars e.g. 3 mm in thickness andsituated in a direction perpendicular to the vibratory conveyor. Thesecond unit 22 with the rods 23 is located about 1.5 to 2 cm over thesieve bottom 17.

The distance between sieve bottom 17 and the second bottom 2" is some 2cm plus the layer thickness to be expected of the material to betreated.

As the mesh size of the sieve bottom 1 relates to the average grain sizeof the finished product one may possibly regulate at least withincertain limits, the grain size of the product.

What I claim is:
 1. A method of treating finely divided oil containing vegetable raw materials with moisture and heat, said method comprising conveying the finely divided raw materials on a perforated member longitudinally from a rear portion thereof to a front portion thereof, vibrating said perforated member to effect the conveying of the raw materials, introducing steam through a first upstream region of the perforated member from beneath the perforated member for treating said raw materials, introducing a heated gas through a second downstream region of the perforated member for drying said raw material, the steam tending to form agglomerates of said finely divided raw materials on said perforated member, pulverizing said raw materials on said perforated member in said first region to prevent formation of agglomerates of said raw materials, and forming a step in said perforated member in said first region to cause the pulverized material to drop from one level to another in counter current with the incoming steam such that any dust formed during pulverization becomes bound to the pulverized material.
 2. A method as claimed in claim 1 comprising dividing said first and second regions by a vertical partition extending a small distance above the perforated member.
 3. A method as claimed in claim 1 comprising effecting said pulverizing by mounting a plurality of fixed rods above said first region of said perforated member and a plurality of movable rods adjacent the fixed rods and coupled to the perforated member for movement therewith.
 4. A method as claimed in claim 1 comprising recirculating fluid extracted from said first region after treatment of said raw material back to said first region after mixture with fresh stream.
 5. A method as claimed in claim 3 wherein said movable rods are formed with a spacing substantially equal to the stroke length of the perforated member.
 6. A method as claimed in claim 5 wherein said fixed rods are formed with a spacing substantially equal to the stroke length of the perforated member. 